openrisc: Add syscall details to emergency syscall debugging

When bringing linux on the or1k Marocchino we ran into issues starting
init.  This patch adds the syscall number and return address to
assist tracing syscalls even before strace is able to be used.

By default this is all disabled but a developer could adjust the ifdef
to enable debugging.

Cc: Andrey Bacherov <bandvig@mail.ru>
Signed-off-by: Stafford Horne <shorne@gmail.com>
This commit is contained in:
Stafford Horne 2022-01-30 17:38:51 +09:00
parent 29bbb2a90f
commit a0a94bc9a6

View file

@ -601,7 +601,7 @@ UNHANDLED_EXCEPTION(_vector_0xb00,0xb00)
*/
_string_syscall_return:
.string "syscall return %ld \n\r\0"
.string "syscall r9:0x%08x -> syscall(%ld) return %ld\0"
.align 4
ENTRY(_sys_call_handler)
@ -679,15 +679,25 @@ _syscall_return:
_syscall_debug:
l.movhi r3,hi(_string_syscall_return)
l.ori r3,r3,lo(_string_syscall_return)
l.ori r27,r0,1
l.ori r27,r0,2
l.sw -4(r1),r27
l.sw -8(r1),r11
l.addi r1,r1,-8
l.lwz r29,PT_ORIG_GPR11(r1)
l.sw -12(r1),r29
l.lwz r29,PT_GPR9(r1)
l.sw -16(r1),r29
l.movhi r27,hi(_printk)
l.ori r27,r27,lo(_printk)
l.jalr r27
l.nop
l.addi r1,r1,8
l.addi r1,r1,-16
l.addi r1,r1,16
#endif
#if 0
_syscall_show_regs:
l.movhi r27,hi(show_registers)
l.ori r27,r27,lo(show_registers)
l.jalr r27
l.or r3,r1,r1
#endif
_syscall_check_trace_leave: